Milling machine



3 F. A. HASSMAN 1,940,126

MILLING MACHINE Filed Jan. 25, 1930 2 Sheets-Sheet l F. A. HASSMANMILLING MACHINE Dec. 19, 1933.

2 Sheets-Sheet 2 Filed Jan. 25, 1930 1 l if M W A m; w

Patented Dec. 19, 1933 1,940,120 7 p MILLING MACHINE "Fred A.llassmamClncinnati, Ohio, asslgnor m j V The Cincinnati Milling MachineCompany,

I Cincinnati, hio, a corpora tion of Ohio 1 V I Kpplicationlanuary 251930. Serial No. 423,523

' 3Clahn's. (oroo j-m i This invention relates to milling machines andmore particularly to a device for counterbalancing'thespindle heads onvertical type machines.

One of the principal objects of this invention I is :the provision of animproved counterweight for vertical milling machines, that will occupy"a smaller amountof space and thus be adapted to fit in the. gooseneckportion of the column.- It has b'ee'n'common practice to providecounterweights for vertical spindle'heads of milling machines but thesecounterweights are usually suspended in the vertical part of the column.In prior machines this was feasible, as the interior of the column wasnot used for any purpose except perhaps for a single transmission lineto rotate the spindle. In accordance with more recent developments,however, the space in the column has been taken up, such as theinstallation of change boxes of one type or another, and it has beennecessary to provide a new and improved type of counterweight which willoccupy less space without loss of efficiency.

Another object of this invention is the provision of an improvedcounterbalancing mechanism adapted to be directly connected to thespindle head.

Other objects and advantages-of the present invention should be readilyapparent by reference to the following specification, considered inconjunction with the accompanying drawings illustrative of oneembodiment thereof, but it will be understood that any modifications maybe made in the specific structural details hereinafter described, withinthe scope of the appended claims, without departing from or exceedingthe spirit of the invention.

Referring to the drawings, in which like reference numerals indicatelike parts:

Figure 1 is a plan view of the end of a gooseneck column;

Figure 2 is a vertical section on the line 22 of Figure 1;

Figure 3 is a section on the line 3-3 of Figure 1;

Figure 4 is a section on the line 4-4 of Figure 1; and

Figure 5 is a diagrammatic view showing the location of thecounterweights in the old style machines.

The reference numeral indicates the overhanging portion of a gooseneckcolumn having vertical guideways 11, in which is slidably mounted thespindle head 12 which carries the rotatable spindle 13. Spindle 13 has abevel gear 14 splined thereto which is driven by the bevel gear 15 attached to the end of the horizontal shaft 16. The shaft 16 may be drivenby a prime mover in any suitable manner. It will be noted from Figure 1that theshaft 16 is centrally mounted in the column." r

The spindle head has attached to its rear portion the rack 17 which isoperatively engaged by the gear 18 mounted on the end of thestub shaft19 Journaled in the columnand havingthe handle 20 on the outerendthereof. The rack 1'7 has directly connected thereto, by means of thepin 21 and the chain 22, the counterweight 23. The chain 22 passes overthe sprocket 23, which is pinned to the shaft 24 journaled in the upperpart of the column. On the other end of the shaft 24 is another sprocketwheel 25, keyed thereto, overwhich passes the chain 26 having one endattached to the sprocket wheel as by the bolt 27 and the other endattached to the counterweight 28. The chains 22 and 26 are attached tothe (5 Weights by means of the bolt 29 passing through the center of theweight and having a nut and washer on the lower end thereof.

It will be noted that the counterbalance for the spindle head has beendivided into two so weights. This is necessary for two reasons, first,to prevent interference with the shaft 16 which passes through thecenter part of the column and, second, in order to make the weightsshorter and confine them in a smaller space. It will be '86 noted fromFigure 5, which shows the old construction, that the length of theweight was immaterial. Attention is also called to the fact that thechain 22 is connected direct to the head, although it could be wound upon the shaft 19. It is preferred, however, to connect it direct to thehead, as it relieves the teeth of the rack and gear of the strain ofbeing under constant tension. An opening 30 is provided in the top ofthe column for the convenient insertion of the weights into the column.

What is claimed is:

1. A milling machine having a column with a laterally curved upperportion forming an overhanging chamber having parallel side walls, saidshaft to the spindle, means to effect vertical adproximating the weightof said carrier, and means connecting the cross shaft to said headwhereby upon adjustment of the head all of said weights will coact tocounterbalance the head. I v

2. In a milling machine having a columnwith a projecting, over-hangingportion, said portion forming an inclosed chamber the combination of aspindle head mounted on said portion for vertical movement, a cutterspindle journaled in said spindle, and means self-contained within saidchamber for counterbalancing the spindle head, the depth of said chamberbeing less than :the range .ofmovement necessary for a'singlecounterweight for the spindle carrier comprising a shaft journaledtransversely. of the chamber andin the upperpart thereof, sprocketwheels mounted on each end of the shaft,- a'first weight, supportingmeans for the weight passing'over and attached to one sprocket wheel, asecond weight, supporting means therefor passing over the other sprocketwheel and attached to said head, and mechanism for effecting verticalmovement of the spindle head whereby movement of one weight by the headwill automatically cause movement of the other weight, the sum of saidweights approximating the weight of said head.

3. A milling machine comprising a column, an overhanging portionprojecting from the column and forming an inclosed chamber, guidewaysformed on the free end of said portion, a spindle carrier slidablymounted in said guideways, a cutter spindle journaled in said carrier, apower shaft rotatably mounted centrally 01' said chamber. for rotatingthe spindle, said shaft dividing thechamber into two portions, the depthof said chamber being less than the range of movement necessary for asingle counterweight said head, power actuated meansfor rotating for thespindle carrier, means to counterbalance the carrier comprising a pairof weights suspended on opposite sides of said shaft, means operativelyconnecting one of said weights to the head for joint movement therewith,means operatively connecting the remaining weight to. the first weightfor actuation thereby, and manually operable rack and gear meansfor-effecting adjustment of the carrier. l a J V a v FRED -A. HASSMAN.

